This invention relates to a spun yarn having novel structure and a method of producing the same.
Recently, in order to obtain a variety of spun yarns which had appearances and feeling different from those of ring spun yarns and to perform a greatly increased spinning speed, there have been successively proposed an open end spinning process, false twist spinning process, etc. Such spun yarns thus produced were inferior to the ring spun yarns with regard to yarn uniformity, yarn strength, feeling, etc. Thus, satisfactory spun yarn cannot yet be obtained. The conventional process disclosed in Japanese Patent Publication No. 28250/1968 provides yarn twisted by a torque jet under no control resulting in no avoidance of the end of the staple fiber bundles over its aspirating jet. The staple fiber bunches thus tightened by twist do not have almost relief of twist. Therefore, the process necessitates a large number of free-ended fibers with the sliver fed at part of the front rollers being in a state of ribbon. The staple yarn thus spun has a yarn structure which has non-twisted wadding thread or core portion and is surrounded by the free-ended fibers of aforesaid ribbon shape on the outer periphery thereof (see FIG. 1). Further, both the nozzles were turned in opposite direction to each other as the improvement therefore, but better result cannot be obtained thereby.
Another conventional method of producing the spun yarn disclosed in Japanese Patent Publication No. 71226/1974 has indispensably provided a holding region under low tension of the staple fibers at the intermediate between a pneumatic nozzle and a false twisting nozzle with no respect to the normal or reverse rotating direction against the difficulties of spinning control by the width of the ribbon, but did not still disclose any propagation of twisting by a second nozzle over the holding region under low tension to the first nozzle. In such conventional method, the twisting caused by the first and second nozzles are intersected to each other in the holding region under low tension with the result that this method can produce SZ random twisted yarn (see FIG. 2).